Objective To evaluate the growing condition of osteoblasts, which were cultured on the silicatephosphate coating on the surface of the magnesium and the biocompatibility between the coating and osteoblasts. Methods The osteoblasts were harvested by collagenase digesting method,and identified by immunofluorescence and Alizarin red staining method.Then the osteoblasts of the forth passage were inoculated on the material surface and the changes in form of osteoblasts on different surfaces were observed by scanning electron microscopy(SEM).At the same time the material leaching liquor was prepared to culture osteoblasts and the viabilities and differentiation of osteoblasts were detected by MTT and ALP method respectively. Results SEM showed that cells on the coating magnesium alloy growed well, and proliferated significantly,but cells were hardly finded on the naked group. The MTT and ALP analysis showed that 1%-5% of Si coating could promote the growth,proliferation and differentiation of osteoblast more obviously than other groups EM>in vitro/EM>. Conclusion The silicatephosphate coating on the surface of the magnesium had good compatibility with osteoblasts and was conducive to cell growth ,adhere, prolif